The standard Fourier metrics used for assessing image quality in computed tomography (CT) use a planar (2D) formulation of the noise equivalent quanta (NEQ) without a specific concept to manage the influence of longitudinal resolution variations, thus create a bias in the comparison of image quality for different reconstructed slice thicknesses. For this work, we designed a ‘slice NEQ’ that takes the longitudinal resolution into account and provides a volumetric indication of the scanner imaging performance. We also developed a specific formulation for the system DQE at the CT isocentre. A cylindrical water phantom with three different inserts for three contrast levels (−100, 120 and 1000 HU) was used for the task-based transfer functions (TTF) and noise power spectra (NPS) measurements. The longitudinal TTF was measured using the point source of the Catphan ® 600 phantom. Images of the phantoms were acquired on two scanners (GE Discovery 750 HD and Siemens SOMATOM For...

中文翻译：

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切片NEQ和系统DQE以评估CT成像性能。

用于在计算机断层扫描（CT）中评估图像质量的标准傅里叶度量标准使用噪声等效量子（NEQ）的平面（2D）公式表示，而没有特定的概念来管理纵向分辨率变化的影响，从而在比较中产生偏差重构的不同切片厚度的图像质量 对于这项工作，我们设计了一个“切片NEQ”，它考虑了纵向分辨率并提供了扫描仪成像性能的体积指示。我们还为CT等中心线的DQE系统开发了一种特殊的配方。带有三个不同插入物的圆柱形水模用于三个对比度级别（-100、120和1000 HU），用于基于任务的传递函数（TTF）和噪声功率谱（NPS）的测量。使用Catphan®600幻象的点光源测量纵向TTF。幻影的图像是在两台扫描仪（GE Discovery 750 HD和Siemens SOMATOM For ...